Diagnosis of GE Reflux

Most of the time, just hearing a parent's story and seeing a child
is enough to make the diagnosis of gastroesophageal (GE) reflux, but
sometimes testing may be recommended. These tests are most commonly
used to diagnose GE reflux:

barium swallow or upper GI series

technetium gastric emptying study

pH probe

endoscopy with biopsies

Barium Swallow or Upper GI Series

This special x-ray test allows doctors to follow food down the
baby's esophagus, through the stomach, and into the first part of the
small intestine. The baby is fed a chalky-white liquid called barium. A
video x-ray machine follows the barium through the upper intestinal
tract and lets doctors see if there are any abnormal twists, kinks or
narrowings of the upper intestinal tract. This test does not, however,
give doctors much information on how the intestine works when food is
in it, so it is not a very reliable way of diagnosing reflux.

Note: Many children with severe reflux symptoms will
not demonstrate reflux on a barium swallow
(poor sensitivity) and conversely, children who demonstrate reflux on a
barium swallow may have no symptoms of gastroesophageal reflux (poor
specificity).

Perhaps more important, the severity of reflux observed on a barium
swallow does not help to predict the severity of symptoms of reflux nor
does it help to predict the ultimate outcome. Fewer than 30% of adults
with symptoms of chronic GE reflux demonstrate reflux on a barium
swallow, and fewer than 30% of adults with esophagitis as a result of
chronic reflux demonstrate reflux on a barium swallow.

Technetium Reflux Scan

With this test, the infant drinks milk mixed with technetium, a very
weakly radioactive chemical, and then the technetium is followed
through the intestinal tract using a particular type of camera. This
test is helpful in determining whether some of the milk/technetium ends
up in the lungs (aspiration). It may also be helpful in determining how
long milk sits in an infant's stomach.

pH Probe

With this test, a small wire with an acid sensor is placed through
the infant's nose down to the bottom of the esophagus. The sensor is
usually left in place for 12-24 hours. It can detect when stomach acid
"refluxes" into the esophagus. This information is generally recorded
on a computer. At the conclusion of the test, we can determine how
often the infant "refluxes" and whether there are any symptoms when
this occurs.

Unfortunately, the severity of reflux as measured by pH probe often
doesn't correlate with the severity of symptoms . . . that is, some
infants with very frequent vomiting will have a normal pH probe study.
Perhaps more important, the severity of reflux measured by a pH probe
does not help to predict the ultimate outcome. Although pH probe
analysis is abnormal in nearly 80% of infants with mild reflux symptoms
(i.e. occasional spitting and vomiting), one third of infants with
severe symptoms have a normal pH probe study! Also, fewer than 40% of
infants with severe esophagitis due to chronic reflux will have
abnormal pH probe studies.

Perhaps the greatest potential value of pH probe analysis is in
trying to correlate reflux with unusual or persistent symptoms such as
apnea, stridor, coughing or wheezing, choking, gagging, or unexplained
irritability. If these symptoms occur frequently enough, a pH probe
analysis can determine if these symptoms occur at the same time as
episodes of acid reflux.

Endoscopy with Biopsies

This is the most invasive test. A flexible endoscope with lights and
lenses is passed through the infant's mouth into the esophagus,
stomach, and duodenum, allowing a direct look to see if there is any
irritation or inflammation. In some children with reflux, repeated
exposure of the esophagus to stomach acid causes some inflammation
(esophagitis). The greatest problem with this test is that
most infants with reflux symptoms do not develop esophagitis (less than
half with severe symptoms have esophagitis at endoscopy), so a normal
test does not necessarily mean the child does not have reflux.

Summary

As you can see, none of these tests is perfect. Each has strengths
and weaknesses and provides different information.

In most cases, diagnosis of GE reflux can be made clinically based
on a careful history and physical examination of the child.

In a child whose development is delayed or disordered, it is
appropriate to consider reflux when the child:

suffers from recurrent pneumonia or aspiration,

is chronically irritable without any apparent explanation, or

does not grow well despite receiving adequate numbers of
calories

Diagnostic tests are primarily useful when trying to associate these
types of unusual or severe symptoms with reflux, but offer little
information about the ultimate outcome or appropriate treatment
strategies.